Phenotyping of animal models allows investigators to translate basic observations into clinically meaningful[unreadable] endpoints that are relevant to human nutritional disorders. The mouse has assumed a pivotal role in the[unreadable] translational spectrum from molecule to disease because of the widespread availability of reagents for[unreadable] altering its genome. Traditional transgenesis for overexpression of genes and "knockout" strategies to[unreadable] inactivate gene expression are routine. Regulated expression at specific sites is now possible using tissuespecific[unreadable] promoters and constructs that respond to readily available agents such as tetracycline. Using crelox[unreadable] technology to inactivate gene expression in discrete cell types in mice is widespread. Less readily[unreadable] accessible are the means for characterizing these animal models to yield insight into the mechanisms of[unreadable] common nutritionally-related disorders in humans including obesity, hyperlipidemia, atherosclerosis,[unreadable] diabetes, insulin resistance and hypertension.[unreadable] The principal goal of the Animal Model Research Core is to provide easy access to frequently used[unreadable] mouse models, specialized expertise, and high quality assays to facilitate nutritionally-relevant[unreadable] research and enhance the cost-effectiveness of conducting this research. Over the past five years,[unreadable] the Core has been extremely successful at achieving this goal. Thirty-five laboratories at Washington[unreadable] University have utilized core services during this period. To mention a few of the critical services, the core[unreadable] has provided well-characterized mouse models to 11 different CNRU investigators' laboratories , trained 57 individuals from 16 different laboratories at our institution in techniques including[unreadable] breeding and animal husbandry, performed over 3,100 noninvasive determinations of body composition in[unreadable] mice, and performed more than 33,000 biochemical analyses of mouse serum.